rb25detSpoolin Posted May 28, 2014 Share Posted May 28, 2014 Hi there i have looked a bit everyone and dont know quite whats wrong and how to get my speedo working. My dash cluster is new and 100% working. But still my speedo doesnt move i was told its due to having a rb20det tranny which uses a mechanical speedo while the cars rb25 requires an electrical speedo. I was told that by putting in a rb20e r33 speedo drive would resolve this . Im not too sure on how accurate this is and Id like any tips or ways to resolve the issue. Preferably not too expensive. Im sure many people have done this b4 looking for how to get the speedo working again . (NOTE : previous owners dropped the 20det gbox in , i was told its a small issue but more i looked into it after buying most mechanics have suggested putting in a rb25det bigbox, i dont see the need as the gbox is tight and strong and I am running no modes all stock factory 100,000kms. engine 60,000km tranny ) Quote Link to comment Share on other sites More sharing options...
NewZed Posted May 28, 2014 Share Posted May 28, 2014 The speedometer determines what type of speedometer drive you need. You need to describe your speedometer. If it's a stock speedometer, people could probably figure it out if they knew what kind of car you're working with. Engines don't require speedometers. Quote Link to comment Share on other sites More sharing options...
rb25detSpoolin Posted May 29, 2014 Author Share Posted May 29, 2014 (edited) The speedometer determines what type of speedometer drive you need. You need to describe your speedometer. If it's a stock speedometer, people could probably figure it out if they knew what kind of car you're working with. Engines don't require speedometers. its a stock rb25det gts25t r33 mspec series 1 1994 if that helps . I realise engine doesnt require speedometre i was meaning the stock rb25 r33 uses a electric speedo drive Edited May 29, 2014 by rb25detSpoolin Quote Link to comment Share on other sites More sharing options...
rb25detSpoolin Posted May 29, 2014 Author Share Posted May 29, 2014 I really just wana know what others who had a r33 rb25 with a rb20 tranny did to get there speedo working . Quote Link to comment Share on other sites More sharing options...
wrcbonk Posted May 29, 2014 Share Posted May 29, 2014 This is an excerpt from page 5 of Chris Rummel's wiring write up Speedo - use Navara D21 Ute mechanical gearbox Pinion Assembley Part No 3270202G17 It's what I used and it works, bearing in mind that my diff ratio matched the stock r33 donor. Hope this is helpful. Bill Quote Link to comment Share on other sites More sharing options...
mtnickel Posted June 2, 2014 Share Posted June 2, 2014 From my readings, the smaller rb20 trans uses a slightly different shorter pinion mechanical speedo drive gear. (or at least the rb25de (non-turbo) does and I thought they had the same transmission. I will re-iterate new-zed's question about wanting to know what speedometer you have. You say your dash cluster is brand new. Does this mean you have aftermarket or newer gauges? It's knowing what the actual speedometer requires to know how to adapt it. If it's new, it may require an electrical signal either from the ECU or an electric speedo sender. If you mean you got new original stock datsun gauges, then it's just like stock and you will just need the mechanical pinion adapter that fits. Quote Link to comment Share on other sites More sharing options...
rb25detSpoolin Posted June 4, 2014 Author Share Posted June 4, 2014 From my readings, the smaller rb20 trans uses a slightly different shorter pinion mechanical speedo drive gear. (or at least the rb25de (non-turbo) does and I thought they had the same transmission. I will re-iterate new-zed's question about wanting to know what speedometer you have. You say your dash cluster is brand new. Does this mean you have aftermarket or newer gauges? It's knowing what the actual speedometer requires to know how to adapt it. If it's new, it may require an electrical signal either from the ECU or an electric speedo sender. If you mean you got new original stock datsun gauges, then it's just like stock and you will just need the mechanical pinion adapter that fits. I mean since it was a auto conversion its a new r33 gts25t manual cluster so its stock. Quote Link to comment Share on other sites More sharing options...
mtnickel Posted June 4, 2014 Share Posted June 4, 2014 I mean since it was a auto conversion its a new r33 gts25t manual cluster so its stock. In that case, you are right, you probably need an r33 speedo sender from the smaller rb20 trans. I think a lot of people convert the opposite and put in a mechanical speedo sender to use a stock datsun gauge, so maybe put up a WTB for their stock electric senders. Also, if you check the thread on the mechanical speedo drive, I put a link to a good nissan parts site that lets you cross reference different nissan parts. So if you look up the diagram for the speedo sender you need, you can plug in the part number and determine if other nissans use the same one. I would guess that the KA24 trans uses a similar one as I thought the rb20 trans was based off that, but that's just off the top of my head. If you need help finding the part let me know. Mark Quote Link to comment Share on other sites More sharing options...
zster Posted June 6, 2014 Share Posted June 6, 2014 A little off topic, my speedhut GPS speedo does 0 to 60 times, and more. Somewhat helpful in tuning and is fun. Quote Link to comment Share on other sites More sharing options...
winstonusmc Posted June 6, 2014 Share Posted June 6, 2014 Some of the auto Nissans use the same sender. I used a later 90's Nissan Cima sensor in my R33 Rb20 transmission. The thing about that particular car is that its a V8 with low gears, which works with my 3.56 gears. Silvias and some Laurels should have the same sensor too. Quote Link to comment Share on other sites More sharing options...
BlueRB240 Posted July 6, 2014 Share Posted July 6, 2014 RB20 transmission will fit the 240sx S13 or S14 speed sensor to make it electric. You might need a conversion box tho depending on the cluster your running. Quote Link to comment Share on other sites More sharing options...
illusioneclipse Posted August 29, 2018 Share Posted August 29, 2018 On 5/29/2014 at 12:20 AM, wrcbonk said: This is an excerpt from page 5 of Chris Rummel's wiring write up Speedo - use Navara D21 Ute mechanical gearbox Pinion Assembley Part No 3270202G17 It's what I used and it works, bearing in mind that my diff ratio matched the stock r33 donor. Hope this is helpful. Bill It's what you used for your RB20 transmission? Quote Link to comment Share on other sites More sharing options...
jthom5147 Posted September 10, 2018 Share Posted September 10, 2018 OP: you’re running an R33 cluster? The Navarra speedo gear is for a cable driven speedo gauge / cluster. No it won’t work for an electronic cluster. Quote Link to comment Share on other sites More sharing options...
illusioneclipse Posted September 11, 2018 Share Posted September 11, 2018 19 hours ago, jthom5147 said: OP: you’re running an R33 cluster? The Navarra speedo gear is for a cable driven speedo gauge / cluster. No it won’t work for an electronic cluster. I am running stock 78 280z gauge which is mechanical cable. I searched around and came across Navarra speed sensor for my rb20det transmission. The length of the sensor just seemed too long. It is the right sensor for rb20det transmission with stock 280z gauge? Quote Link to comment Share on other sites More sharing options...
jthom5147 Posted September 12, 2018 Share Posted September 12, 2018 someone on the dpan group found what appears to be a mechanical speedo gear for the fs5w71c trans. Quote Link to comment Share on other sites More sharing options...
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